Kavli Affiliate: John D. Silverman
| First 5 Authors: Lilan Yang, Jeyhan S. Kartaltepe, Maximilien Franco, Xuheng Ding, Mark J. Achenbach
| Summary:
We measure galaxy sizes from $2 < z < 10$ using COSMOS-Web, the largest-area
JWST imaging survey to date, covering $sim$0.54 deg$^2$. We analyze the
rest-frame optical (~5000A) size evolution and its scaling relation with
stellar mass ($R_epropto M_*^alpha$) for star-forming and quiescent galaxies.
For star-forming galaxies, the slope $alpha$ remains approximately 0.20 at $2
< z < 8$, showing no significant evolution over this redshift range. At higher
redshifts, the slopes are $-0.13 pm 0.15$ and $0.37 pm 0.36$ for $8 < z < 9$
and $9 < z < 10$, respectively. At fixed galaxy mass, the size evolution for
star-forming galaxies follows $R_e propto (1+z)^{-beta}$, with $beta = 1.21
pm 0.05$. For quiescent galaxies, the slope is steeper $alphasim 0.5$-$0.8$
at $2 < z < 5$, and $beta=0.81pm0.26$. We find that the size-mass relation is
consistent between UV and optical at $z < 8$ for star-forming galaxies.
However, we observe a decrease in the slope from UV to optical at $z > 8$, with
a tentative negative slope in the optical at $8 < z < 9$, suggesting a complex
interplay between intrinsic galaxy properties and observational effects such as
dust attenuation. We discuss the ratio between galaxies’ half-light radius, and
underlying halos’ virial radius, $R_{vir}$, and find the median value of
$R_e/R_{vir}=2.7%$. The star formation rate surface density evolves as
$logSigma_text{SFR} = (0.20pm0.08),z+(-0.65pm0.51)$, and the
$Sigma_text{SFR}$-$M_*$ relation remains flat at $2<z<10$. Lastly, we
identify a threshold in stellar mass surface density
$logSigma_esim9.5$-$10, M_{odot}/kpc^2$ marking the transition to compact,
quenched galaxies from extended, star-forming progenitors. In summary, our
findings show that the extensive COSMOS-Web dataset at $z > 3$ provides new
insights into galaxy size and related properties in the rest-frame optical.
| Search Query: ArXiv Query: search_query=au:”John D. Silverman”&id_list=&start=0&max_results=3